Method for performing the first steps in converting an open-ended glass tube into a plurality of fever thermometers



Aug. 18, 1964 A. SONNI ETAL 3,145,091!

METHOD FOR PERFORMING THE FIRST STEPS IN CONVERTING AN OPEN-ENDED GLASS TUBE INTO A PLURALITY OF FEVER THERMOMETERS 2 Sheets-Sheet 1 Filed July 21, 1958 INVENTORS /erA/m? J'avv/v/ 4/. ATTORNEY.

Aug, 18, 1964 A. SONNI ETAL 3,145,091

METHOD FOR PERFORMING THE FIRST STEPS IN CONVERTING AN OPEN-ENDED GLASS TUBE INTO A PLURALITY OF FEVER THERMOMETERS 2 Sheets-Sheet 2 Filed July 21, 1958 BY 2 @iw United States Patent METHOD FUR PERFORMING THE FIRST STEPS IN CUNVERTING AN OPEN-ENDED GLASS TUBE INTG A PLURALITY 0F FEVER THERMQMETERS Arthur onni and Anthony Sonni, both of 33-4il 75th St, Jackson Heights, FLY. Filed July 21, 1958, Ser. No. 749,927 2 Claims. (Cl. 65-108) This invention relates to method and apparatus for performing the first steps in converting an open-ended glass tube into a plurality of fever thermometers.

In the past all steps in the manufacture of fever thermometers have been done one at a timeiby a skilled glass blower. He has first divided a tube of lens glass into lengths desired for forming a single thermometer and has then worked with each length, one at a time, heating the length locally and then introducing air under pressure into the tube to provide a first small enlargement of the bore, known as a blister, adjacent one end of the length, and a second enlargement of the bore at the end, which is known in the trade as the opening and is left open, to which he then fused a small length of normal tubing which he converted into a bulb for the mercury. He evacuated the first enlargement or blister thereby drawing the surrounding portion of the glass wall into the evacuated space and causing the bore to divide into two constricted branches extending around the filled in blister. The constriction in the bore thus provided allows mercury with which the bulb is filled to be forced past it when the bulb is heated to a temperature indicating a fever, and holds the resulting column of mercury in the bore so that a temperature reading can be made until a force greater than gravity is used to return the mercury to the bulb-as by shaking the thermometer.

It is the object of this invention to provide method and apparatus by which the manufacture of fever thermometers may be speeded and the enlargement of the bore for the blister, and the enlargement of the bore for the opening may be provided simultaneously for two thermometers.

The invention will best be understood if the following description is read in connection with the drawings in which,

FIGURE 1 is a side elevation partly in cross section and partly broken away of apparatus embodying the invention,

FIGURE 2 is top plan view taken on the line 2--2 of FIGURE 1,

FIGURE 3 is a detail side elevation view showing two sets of flaming gas jets contacting a hollow glass tube simultaneously to soften the tube at two points to form two spaced blisters therein,

FIGURE 3a is a plan view of the disposition shown in FIGURE 3,

FIGURE 4 is a view similar to FIGURE 3 showing the single set of jets withdrawn from the glass tube, and one set of the combination of sets advanced beyond the tube but with its companion set of jets contacting the glass tube intermediate the two blisters.

FIGURE 4a is a plan View of the disposition shown in FIGURE 4.

FIGURE 5 shows a third enlargement of the bore by an air bubble intermediate the tWofblisters with the tube drawn out and weakened around the air bubble at the point of division in preparation for being broken into two parts with the bore enlarged at an end of each part and each part having therein one of said blisters.

FIGURE 6 is a view similar to FIGURE 5, but showing how the bubble at the point of division provides an enlargement or opening at one end of each part of the tube when the latter is divided.

In the embodiment of the invention disclosed herein a stand or other suitable support it) is provided. On member It) a two-part U-shaped bracket 12 is provided which comprises two clamp members 14 and 16 which are aligned vertically and serve to support a hollow ended glass tube T (of lens glass) from which a plurality of fever thermometers are to be formed. One of the clamp members M or 16 is movable relative to the other in a vertical plane in order to elongate a mid-portion of the tube after it has been heated and its bore enlarged with an air bubble, thereby providing a predetermined point for dividing the tube into two parts each of which has been already partly processed for forming a fever thermometer as will be explained.

Also supported on the stand 1% is the upright Ida which supports the horizontal slideways l8 and 20 in which are the slides 22 and 24. Arms 2-6 and 2.8 are pivotally supported at their lower ends on upright lliia by the pivots p, and each is provided at its upper end with a slot s which engages a pin it provided adjacent the rear ends of slides 22 and 24 respectively.

At the forward end of slide Ztl is a cross arm 30 from which there projects in the direction of glass tube T a plurality of sets of arms 32a, 32b and 34a and 34b. Pivotally connected to the forward ends of arms 32a and 32b are the gas jet heads 36a and 3619 respectively from each of which projects a nozzle 11 for directing a gas jet at the glass tube T as will be described. Pivoted to the forward ends of arms 34:: and 3% are similar heads 33a and 38b with similar nozzles n. It will be noted that arms 34:: and 34b are shorter than arms 32a and 32b and this disposition of the two sets of heads is provided so that only one set of gas jets can be effectively directed against glass tube T at one time. When the gas jets from heads 36a and 36]; are directed against glass tube T the gas jets from heads 33a and 33b will be out of contact with glass tube T, and similarly when the gas jets from heads 38a and 38b are directed against the glass tube T the jets from heads 36a and 36b will be directed beyond tube T.

In the forward end of slide 24 is a cross member 449 from which project the arms 42:: and 42b, and at the outer end of these arms respectively gas heads 44a and 44th are provided. The heads 36a, 36b and 33a, 38b provide a combination of two sets of gas jets, while the heads 44a, 44b provide a single set of gas jets. However, since heads .ifia, 38b are offset from their companion set of jets 36a, 3615 the single set of jets 44a, 44b may be moved independently into vertical alignment with the heads 36a, 36b so that when flames from the jets of heads 36a and 361) are directed against opposite sides of the glass tube T at a level indicated by x in FIGURE 3, the flames from jets 4 4a and 44b may be simultaneously directed against opposite sides of glass tube T at a level indicated by y in FIGURE 3.

In order to direct flames from the heads 38a and 38b against glass tube T the operator moves slide 22 further in the direction of glass tube T, and this second step of movement of slide 22 carries the jets from heads 36a and 36b beyond and out of contact with glass tube T and causes the jets from heads 38a and 38b to be directed against opposite sides of glass tube T at a level z, intermediate levels x and y indicated in FIGURE 3.

Gas is supplied to the various heads through flexible conduits having suificient slack so that they do not interfere with the reciprocating movement of the head support arms and their respective slides 22 and 24. Since it is desired to bring the jets from the heads 36a, 36b and 44a, 44b simultaneously against glass tube T at vertically spaced levels such asis indicated by letters x and y in FIGURE 3 it has been found convenient to supply these sets of heads by conduits 46a, 46b, and 48a and 48b leading through a Y-coupling 50 from the conduit 52, and to supply the heads 38a and 38b through conduits 54a and 54b branching from a conduit 56. Conduits 52 and 56 are connected in a similar manner to a source of supply. As illustrated in FIGURE 2 these conduits may be coupled to the tubes 58 and 60 respectively which extend through, and are supported in, a bracket 62 shown mounted on top of slideway 18. Tubes 58 and 60 communicate with the mixing chambers 59 and 61 respectively. Connected to mixing chamber 59 are the air and gas supply lines 63 and 64 controlled by a common needle valve 68 for regulating the respective amounts of air and gas. Similarly connected to mixing chamber 61 are the air and gas supply lines 66 and 67 controlled by a common needle valve 70.

The assembly of slide 24 and its crosshead 40 and its projecting arms 42a and 42b, is shown provided with spring means 72, interposed between a bracket 74 depending from the crosshead 40 and the bracket 76 depending from slideway 20, acting to return the assembly to the left as shown in FIGURE 2. A two-position stop is provided for slide 22 and its two sets of forwardly extending arms 32a, 32b, and 34a and 34b, causing the flaming gas jets from the nozzles of heads 36a and 36b to be directed against the glass tube T when the pivoted arm 26 is against stop 80 in its first position, and causing 'ets from heads 38a and 38b to be in contact with the tube T when arm 26 abuts against the stop in its second position, illustrated in full lines in FIGURE 1.

As shown stop member 80 is the plunger of a solenoid 82 which is attached to the upright a with its plunger in horizontal alignment with a stop member 84 carried by the bracket 86 projecting laterally from arm 26. When plunger 80 is pushed outwardly to the position shown in dotted lines in FIGURE 2, by closing of the solenoid circuit by depressing the foot pedal switch 88, it is in its first control position, and when arm 26 is moved into abutting relation with it the flames from the nozzles of heads 36a and 36b will be directed against glass tube T at the level x. When the foot pedal switch 88 is released the circuit through the solenoid will be opened and plunger 80 will be retracted to the position shown in FIGURE 1 in full lines, which is its second control position, and when arm 26 has moved further to the right into abutting relation with the stop in its second position, the flaming jets from the nozzles 38a and 38b will be directed against tube T at the level 2,, indicated in FIGURE 3.

In the operation of the device the operator may use his left hand to move both arms 26 and 28 while depressing the foot pedal switch 88 in order to place plunger 80 in its first control position. When arm 26 is in abutting relation to stop 80 the operator knows that the flaming jets from heads 36a and 36b are contacting tube T at level x and he moves arm 28 to bring the heads 44a and 44b into vertical alignment with heads 36a and 36b thereby bringing the flames from heads 44a and 44b into contact with the glass tube at level y at the same time that the flames from the heads 36a and 36b are contacting the tube at level x.

As soon as the tube has been softened at level x and level y the operator introduces a pulse of air under pressure into tube T to form slight enlargements b and b of the bore of the tube simultaneously at these two levels. These enlargements are referred to in the trade as blisters and in a later operation, not performed during the steps described herein, these blisters are evacuated causing a constriction within the bore of each fever thermometer slightly above its bulb. For forming the blisters b and b and the intermediate air bubble b to be described an airline 100 is coupled to the lower end of tube T, as by coupling 102, when it is first mounted in the supporting clamps 14 and 16. When the tube T has been heated sufficiently at points x and y as described above, the operator may use his right hand to turn on and off a valve to provide the air pressure momentarily in order to form blisters which in FIGURES 4 and 5 are identified as b and 17 As shown herein the compressed air is provided from any suitable source through conduit 104 into the manifold 105 from which it flows both into control chamber 106 which connects with conduit 100, and control chamber 107 which connects with conduit 108.

The flow into conduit 100 is controlled by solenoid valve 109 which in turn is actuated by the microswitch 110, the switch arm 111 of which is normally maintained in open position by spring 112 so that the supply of air to conduit 100 will be cut olf instantly the operator raises his finger from the control arm 111.

The flow into conduit 108 is controlled by needle valve screw 113. By operation of 113 a stream of cooling air may be directed through conduit 108 against the external surface of the glass tube to harden it after each time it has been softened at levels x, y and 2, as described above.

After the air bubbles or blister b and b have been simultaneously formed in the bore of tube T, the tube is heated at the level 2, FIGURE 3, by means of flames from heads 38a and 38b, and a pulse of air under pressure is again introduced to expand the bore at level z and form the air bubble b When this has been done, and while the tube remains heated at level 2, one of the holders 14 or 16 is moved away from the other to elongate the portion of the tube containing the bubble 12 thus indicating and providing a place for the tube to be broken on a line passing transversely through the enlarged portion of the bore containing the air bubble b When the tube is broken the bore at one end of each resulting length will be open and enlarged and a bulb of a different type of glass is later fused to each of said ends.

As shown herein bracket 12 comprises the slide 116 which carries the movable arm 117 on which clamp 16 is supported, and the slideway 118 comprising the fixed horizontal arm 120 on which the clamp 14 is supported. Slide 116 is made a little shorter than slideway 118 so that a space 128 is provided into which the slide may be moved downwardly, against the action of spring 129, after the glass tube has been heated at tube level z, to elongate the glass tube and weaken it where the bore has been enlarged by the bubble b Slide 116 is movable a short distance downwardly with respect to slideway 118 by operation of handle 122 which rotates the cam eccentric 124. Eccentric 124 rides on the upper end of the angle shaped member 126 which is connected to the slide 116.

After the blisters have been formed, and the tube T has been elongated to facilitate breaking it on a line passing through the portion of the bore enlarged by bubble b the tube is removed from clamps 14 and 16, ending the operation performed in the apparatus disclosed herein.

By means of the apparatus described herein the steps of forming a blister and enlarging one end of a thermometer barrel are performed simultaneously for two thermometers thus substantially halving the time previously required for these steps in the manufacture of two thermometers.

There has thus been provided method and apparatus in which the above stated objects are achieved in a thoroughly practical manner.

What we claim is:

1. The method of manufacturing fever thermometers which comprises, holding a glass tube stationary in vertical position, applying heat substantially simultaneously to two vertically spaced cross sections of the tube, and, simultaneously with heating said cross sections, supplying air under pressure into the tube to cause its bore to expand at said cross sections and thus forming two spaced are-spar.

blisters allowing said cross sections to cool, applying heat to a third cross section of the tube intermediate said spaced apart cross sections, and, While the tube is softened at said third cross section, supplying air under pressure into the tube momentarily to expand the bore of the tube at said third cross section to form a third blister, and thereafter applying elongating force to the tube to stretch it and elongate said third blister as Well as the tube and to facilitate breaking the tube along a cross section of the tube intermediate the ends of said third blister.

2. The method of manufacturing fever thermometers which comprises holding a glass tube stationary in vertical position, applying heat substantially simultaneously to two vertically spaced cross-sections of the tube by heating the tube at each of said cross-sections by jets of flame directed against the tube While it is stationary, and simultaneously with heating said cross-sections supplying air under pressure into the tube to cause its bore to expand at said crosssections and form two spaced blisters, allowing said cross-sections to cool, and applying heat to a third crosssection of the tube intermediate said spaced apart cross-sections by directing a plurality of jets of flame against the tube at said third cross-section While holding the tube stationary, and while the tube is softened at said third cross-section supplying air under pressure into the tube momentarily to expand the bore of the tube at said third crosssection and form a third blister, and thereafter applying elongating force to the tube to stretch it and elongate said third blister as well as the tube to facilitate breaking the tube along a cross-section of the tube intermediate the ends of said third blister.

References Cited in the file of this patent UNITED STATES PATENTS 304,896 Barry Sept. 9, 1884- 626,124 Yankauer May 30, 1889 1,685,349 Bailey Sept. 25, 1928 1,866,904 Pingen July 12, 1932 1,888,635 Koenig Nov. 22, 1932 2,215,980 Schreiber Sept. 24, 1940 2,282,993 Dichter May 12, 1942 2,410,345 Hinkley Oct. 29, 1946 2,582,818 Coby Jan. 15, 1952 FOREIGN PATENTS 934,432 Germany Oct. 20, 1955 

1. THE METHOD OF MANUFACTURING FEVER THERMOMETERS WHICH COMPRISES, HOLDING A GLASS TUBE STATIONARY IN VERTICAL POSITION, APPLYING HEAT SUBSTANTIALLY SIMULTANEOUSLY TO TWO VERTICALLY SPACED CROSS SECTIONS OF THE TUBE, AND, SIMULTANEOUSLY WITH HEATING SAID CROSS SECTIONS, SUPPLYING AIR UNDER PRESSURE INTO THE TUBE TO CUSE ITS BORE TO EXPAND AT SAID CROSS SECTIONS AND THUS FORMING TWO SPACED BLISTERS ALLOWING SAID CROSS SECTIONS TO COOL, APPLYING HEAT TO A THRID CROSS SECTION OF THE TUBE INTERMEDIATE SAID SPACED APART CROSS SECTIONS, AND, WHILE THE TUBE IS SOFTENED AT SAID THIRD CROSS SECTION, SUPPLYING AIR UNDER PRESSURE INTO THE TUBE MOMENTARILY TO EXPAND THE BORE OF THE TUBE AT SAID THRID CROSS SECTION TO FORM A THIRD BLISTER, AND THEREAFTER APPLYING ELONGATING FORCE TO THE TUBE TO STRETCH IT AND ELONGATE SAID THIRD BLISTER AS WELL AS THE TUBE AND TO FACILITATE BREAKING THE TUBE ALONG A CROSS SECTIN OF THE TUBE INTERMEDIATE THE ENDS OF SAID THIRD BLISTER. 